[Attributor] Use getAllocaAddrSpace to get address space for AllocaInst

Author: shiltian

llvm/lib/Transforms/IPO/AttributorAttributes.cpp

@@ -12603,6 +12603,13 @@ struct AAAddressSpaceImpl : public AAAddressSpace {
     auto CheckAddressSpace = [&](Value &Obj) {
       if (isa<UndefValue>(&Obj))
         return true;
+      // Some targets relax the requirement for alloca to be in an exact address
+      // space, allowing it in certain other address spaces instead. These
+      // targets later lower alloca to the correct address space in the
+      // pipeline. Therefore, we need to query the data layout to determine the
+      // appropriate address space.
+      if (isa<AllocaInst>(&Obj))
+        return takeAddressSpace(A.getDataLayout().getAllocaAddrSpace());
       // If an argument in flat address space only has addrspace cast uses, and
       // those casts are same, then we take the dst addrspace.
       if (auto *Arg = dyn_cast<Argument>(&Obj)) {